LLVM Weekly - #84, Aug 10th 2015

Welcome to the eighty-fourth issue of LLVM Weekly, a weekly newsletter
(published every Monday) covering developments in LLVM, Clang, and related
projects. LLVM Weekly is brought to you by Alex
Bradbury. Subscribe to future issues at
http://llvmweekly.org and pass it on to anyone else you think may be
interested. Please send any tips or feedback to asb@asbradbury.org, or @llvmweekly or @asbradbury on Twitter.

News and articles from around the web

Adrian Sampson has written a fantastic introduction to
LLVM. It's titled LLVM for Grad
Students, but it should be useful for anybody looking to use LLVM or just
wanting to understand it better.

On the mailing lists

Rong Xu has shared an RFC for late instrumentation in
LLVM. The
RFC describes (and quantifies) the performance cost of inserting
instrumentation for profile-guided optimisation in the frontend and proposes
approaches for adding instrumentation in the middle-end instead.

Asking for advice on how to get started with LLVM is very common. Few take
as much time on detailing their background, motivations, and proposed plan as
Arno Bastenhof in a recent
message.
Probably because of this, his request has attracted some very high quality
replies.

LLVM commits

A handy new LLVM Support header was introduced. The TrailingObjects template
class abstracts away reinterpret_cast, pointer arithmetic, and size
calculation needed for the case where a class has some other objects appended
to the end of it. r244164.

Initial documentation for the Machine IR serialization format has been
written. r244292.

Uniquable DICompilerUnits have been disallowed. Old bitcode will be
automatically upgraded and the sed script in the commit message should be
useful for updating out-of-tree testcases.
r243885.

All of the TargetTransformInfo cost APIs now use int rather than unsigned.
r244080.

Clang commits

A new checker for code-level localizability issues on OSX/iOS was born. It
will warn about the use of non-localized NSStrings passed to UI methods and
about failing to include a comment in NSLocalizedString macros.r244389.

New AST matchers have been introduced for constructors that are default,
copy, or move. r244036.

Other project commits

The old COFF linker in LLD has been removed in favour of the new, faster,
and simpler implementation. r244226.